Franz joseph  weiss



(No Model.)`

F. J. WEISS.

. VALVE. l

No. 559,31@ Y j PawntedApr. 28,1896,

= NirE" rerEs| Il.;

ERA-'NZ JoSEPn WEISS, or BASLE, SWITZERLAND.

VALVE.

SPECIFICATION forming part of Letters Patent No. 559,316, dated April 28, 1896.

" Applicationliled December 11, 1893. Serial No. 493,406. (No model.)

To @ZZ `wiz/om t may concern.'

Be it known thatI, FRANZ JOSEPH WEISS, of the city of Basle, in the canton of Basle and Republic of Switzerland, have invented a certain new and useful'lmprovement in Valves, of which the followingis a specification, reference being had to theaccompanying drawings.

My invention relates to valves for air-pumps and steanrengines, the term air-pumps being here understood in the broadest sensethat is to say, as including also vacuumpumps, compressors, blowers, and all similar machines of this class.

The object of my invention is to provide. means whereby, in air-pumps, the sectional area of the suctionport for the air and, in steam-engines, the sectional area of the dis` charge-port for the steamwill at once7 upon the respective port being opened, be increased preferably to double the usual size, so that the air being sucked into and the steam es! caping from the cylinder, respectively, will be less impeded or throttled in its passage, and consequently, inthe case of a steam-engine, the pressure of the steam will at once, upon the discharge-port being opened, be correspondingly reducedfthat is to say, in common steam-engines it will be reduced to the pressure of the outer atmosphere and in conthe condenser.

My invention consists in the particular arrangement and combination of parts, as hereinafter more fully described with reference to the accompanying drawings.

Figure l is a vertical longitudinal section of a slide-valveaud its valve-face embodying my improvement. Fig. 2 is a similar section of a cylinder and connected valve chest, showing my improved valve-gear as applied thereto.

The valve consists of the two connected portions C and B, the latter, hereinafter called the bridge, being incased in the former and so connected therewith as to provide an intermediate space or channel. The laps on the outer portion C extend inwardly to such a distance only as to leave open spaces r at the ends of both cylinder-ports a when the slide-valve is in the central position shown in Fig. 1, so that in this position both spaces of the cylinder will be in communication with each other.

The valve-face iS of the usual construction,

`with this` exception only, that, according to inlet for the air and, in the case of a steamengine, with the discharge outlet for the steam, will thereby be caused to communicate with the one or the other of the two cylinderports a, while the outer space E will at the same time be caused to communicate with the respective opposite cylinder-port. It will of course be understood that, in the case of an air-pump,the Said space E outside of the slidevalve B C forms the pressure-spacethat is to say, the space into which the air is pressedwhile, in the case of a steam-engine, it is the space into which the steam from the boileris a introduced. densingengines to the pressure prevailing' in Now it will be seen that while in the movement of the valve, as above referred to, but one communication between the space E and the respective cylinder-port will be formed, the effect of the hollow portions or recesses A on the valve-face, and of the recess A in the lower surface of the bridge B of the slidevalve, will be that two communications will be formed simultaneously for connecting the space D with the other cylindereport, asindicated in Fig. 2 by the two arrows originating from the Space D, and that each of `the latter communicating passages will be of the same width as the one communicating passage at the opposite cylinder-port. Thus the sectional area of the comm uncatin g passages connecting the space D with the one or the other side of the cylinder will actually be doubled.

Supposing the valve-rod in the position shown in Fig. 2 to be moving in the direction of the arrow, and the eccentric for actuating IOO the valve to be so mounted as to lag behind by ninety degrees in respect of the crank, as required in air-pumps with distrib utingvalve motion, then the valve will be in about the position shown and will likewise move in the direction indicated by the arrow. Fig. 2 will then illustrate the cylinder of an air-pump, or of a pump generally, wherein the air or the liquid to be pumped will be sucked through the space D and discharged under pressure through the space E. It will be seen that the suction-opening at the port c, as well as at the inner valve portion or bridge B, will still correspond in width to the full sectional area of the port, although the piston Will have nearly reached the end of its stroke and the outlet-passage for the air at the valve will already have been reduced to about half of the full width of the port a. Thus when the cylinder forms part of a compressor or foreing-pump it will, toward the end of the stroke when the speed of the piston has already become reduced, still be capable of being filled with air having the full atmospheric pressure, even if at the middle part of the stroke where the piston moves with its greatest speed the cylinder-space should have become iilled with rareiied air only.

In order to adapt the arrangement shown in Fig. 2 to the conditions of a steam-engine, nothing more is required than that the space D be made to connect either with the open air or with a condenser and the space E with a steam-conduit from any suitable boiler, all the parts in every other respect remaining as shown in the drawings and their relative positions not being materially altered. IIowever, the direction of the arrows in. Fig. 2 would in that ease have to be reversed. Under these conditions the steam-engine here supposed to be provided with the devices shown would run in the opposite direction to that of the airpump previously referred to. It will thus be seen that in the case of a steamengine as well the total of the sectional areas of the outlets at their narrowest portion will be doubled, and that the same will almost at the beginning of the stroke have become equal to the width of the port a, so that the cylinder will actually at the very beginning of the stroke be capable of discharging the steam which during the previous stroke has served for driving the piston, and that the counterpressure of the steam will thus as quickly as possible be reduced to the same pressure as that prevailing in the space into which the steam is being discharged.

It will also be seen that in order to really secure the advantage of the double opening of the air-inlet or steam-outlet ports in the valve-gear shown two communincating passages (or negative laps r must be made to open when the valve is in its central position. For if the laps of the outer valve portion C were extended inwardly, so as to fully cover the ports a or even to extend beyond the inner edges of the latter when the valve is in its central position, then the passages at the inner valve portion or bridge B, it is true, would still become doubled; but this would then not be of any practical use, because in that case the openings at the ports a would become smaller than the doubled passages at the inner valve portion B. Thus by reason of the necessity of providing the passages r, which connect the two cylinder-spaces at the central position of the valve, I obtain as a concomitant feature of this valve an equalization of pressure in the two cylinder-spacesat the time when the valve is in its central position, or, in other words, at the time when the piston is at or near its dead-point. This secures the following advantagespthat is to say:

First. In the case of an air-pump the volume effect is increased, because the air, becoming compressed within the noxious space in front of the piston, escapes into what was previously the suction-space, to be thence during the next stroke of the piston carried away with the quantity of air previously sucked into the cylinder.

Second. In the case of a steam-engine a saving of steam is obtained, because at the end of the stroke the steam before being discharged is caused to communicate with the noxious space in the opposite end of the cylinder, thus increasing the pressure or weight i of the steam therein, so that upon the valve being opened again less steam from the boiler will be required for reiilling the said noxious space.

I am aware that such equalization of pressure, although perhaps not practically employed in steam-engines heretofore, is per se known, and I therefore do not claim this feature as my invention. The same has been here mentioned merely for this reason, because it presents itself as a necessary concomitant feature of my improved valve.

In constructing for this valve the valve diagram of Zeuners it will be observed that in the case of an air-pump the side indicating the discharge and in the case of a steam-cir gine the side corresponding to the admission will not differ in any way from the usual kinds of valves, but that in the case of an air-pump the admission side and in the case of a steam-engine the discharge side will be entirely different from the usual kind, as the ports upon being opened (and also when being closed) are opened to double the width, as compared with the opposite ports, and the conditions may, according to the circumstances of any particular case, be so chosen that the doubling of the sectional areas will continue until the full sectional area of the ports a will have been attained.

Having thus fully described my invention, what I desire to claim and secure by Letters Patent is- The combination with a cylinder having IOO IIO

1o through the port D and bridge Will be double the area of the port a on the opposite side, substantially as described.

In testimony whereof I have signed my naine to this specification in the presence of two subscribing Witnesses.

FRANZ JOSEPH VEISS.

Vitnesses GEORGE GIFFORD, THEoDoRE STAEHELING. 

